Transfer lamination is a process by which a layer of material is applied to a substrate. Generally, transfer lamination involves bonding a transfer film having a application layer, e.g., a metallized layer, to a paper substrate, stripping the film from the substrate leaving the application layer, and then applying a coating to the layer to facilitate printing. As will be appreciated, this process typically involves multiple, separate steps.
In particular, the transfer film is coated in an initial step with a breakaway layer that allows the film to be stripped from the substrate while leaving the application layer and the breakaway layer on the substrate. After the film is coated, the application layer is applied, e.g., the film is metallized. Once the film has been metallized, an adhesive is applied and the film is then bonded to the substrate and the film/substrate is cured typically in an oven. Once removed from the oven, the film is stripped away and the substrate is coated and placed again in the oven to complete the process.
A drawback to this method is that the breakaway layer is applied to the transfer film in a step separate from the transfer lamination process. As will be apparent, each manufacturing step has associated costs and it is generally desirable to reduce such costs through a simplified process with as few manufacturing steps as reasonably necessary.
Moreover, the film used in the transfer of the application layer is typically discarded, or reused only a limited number of times, after it is stripped from the substrate due to the costs of reuse/recycling.
Used transfer film also presents disposal and recycling problems as such films are generally manufactured from polyesters such as polyethylene terephthalate, (“PET”), which are not easily recycled/remanufactured. In particular, plastic films are difficult to remanufacture in that individual characteristics of potentially remanufactured products vary considerably. Likewise, the variety of extruded resins in such films pose significant recycling challenges.
These challenges are evidenced by the fact that presently only about 4.5% of all waste plastic film is recycled in the United States and plastic film makes up approximately 3.1% of all landfilled municipal solid waste. In view of the above, it is desirable to have a transfer film that can be used a large number of times.
Moreover, is also generally desirable to create two usable end products, e.g., the metallized paper substrate and the used film, during a single inline lamination process, regardless of the specific end use of the film. In particular, it is desirable for used film to have multiple potential uses including, for example, use of the film as box wrap, gift wrap and the like, in addition to reuse in a subsequent lamination process. As will be appreciated, this maximizes resources and provides significant manufacturing advantages. Such benefits are unattainable with known processes.
It is also desirable to coat a transfer film for a subsequent use in which the film is embossed or printed. This provides a great deal of flexibility in the end use of a used transfer film again maximizing resources and providing a significant environmental benefit.
As such, a need exists for a method and apparatus for transfer lamination which provides an ease of manufacture and cost savings currently unavailable with known processes. A need also exists for a transfer lamination process that does not require the disposal and/or recycling of a transfer film after a limited number of laminations. As discussed in detail herein, the present invention addresses these needs.